One of the most important concerns of public health systems across the world is controlling or reducing the spread of infectious diseases. This concern is particularly acute in hospitals and other medical care and testing facilities where ill patients come into contact with caregivers, other patients, and visitors. These facilities employ elaborate measures to reduce this risk, including not only mandatory hand-washing and frequent sanitization of equipment, furniture, walls, and floors, but also use of disposable products, such as syringes and hypodermic needles, gloves, bandages, etc. Additionally, great care is taken in disposing of medical waste, particularly biomedical waste.
Biomedical waste includes blood and blood products, tissues removed during surgery and disposable items used and discarded in the normal course of surgical and other medical procedures. Many cities and states mandate special processing of biomedical waste, typically by incineration, autoclaving, or chemical sterilization, to destroy disease-causing pathogens before allowing the waste into local landfills. However, incineration and autoclaving are expensive in terms of their energy usage and affect on local air quality, and chemical sterilizers are typically toxic, posing additional risks to waste-management workers and the environment.
In response to these shortcomings, some waste-treatment processors have built systems that sterilize waste using ozone gas, a form of oxygen that reverts to natural oxygen after performing its sterilization function. For example, U.S. Pat. No. 7,550,111 describes a vertically oriented machine that drops biomedical waste from a top-mounted hopper through a shredder into an ozone-treatment chamber. The chamber holds and exposes the shredded waste to ozone for a period of time, such as 15 minutes, before conveying into a collection bin for later transport to a landfill.
One problem that the present inventors recognized with this system is that its waste-processing speed (throughput) is less than desirable for some medical facilities. The low throughput can result in prolonged storage of unsterilized waste as it awaits processing, exposing staff and patients not only to unpleasant odors, but also to a risk of infection.
Accordingly, the present inventors identified a need for better ozone-based biomedical waste processing systems.